Modern wireless communication devices can utilize radio frequency (“RF”) modulators to convert various types of source signals to modulated signals for transmission to receiving devices. For example, an RF modulator at a first cellular phone can convert voice signals collected from a user via a microphone to modulated RF signals. The first cellular phone can then transmit the modulated RF signals via a wireless mobile network to be received by a second cellular phone. The second cellular phone can then reproduce the voice signals from the user based on the received RF signals.